copyUrl.js

function copy(fileUrl, docUrl, event, trace){
   if( !trace ){
      trace = 0;
   }
   if( !trace ){
      event = new EventEmitter();
   }
   if( trace == MAX_TRACE ){
      logger.error('Max trace exceeded. ({fileUrl} -> {docUrl})'.format({fileUrl: fileUrl, docUrl: docUrl}));
      return undefined;
   }

   logger.info('copy {fileUrl} to {docUrl}'.format({fileUrl: fileUrl, docUrl: docUrl}));
   var src = httpUtil.parseUrl(fileUrl);
   var dst = httpUtil.parseUrl(docUrl);
   var srcReq = src.client.request('GET', src.path,
                                   src.headers);
   srcReq.on('response', function(srcRes){
      if( srcRes.statusCode >= 300 && srcRes.statusCode < 400 &&
          srcRes.headers.location ){
         logger.info('changed url  {fileUrl} to {newUrl}'.format({fileUrl: fileUrl, newUrl: srcRes.headers.location}));
         copy(srcRes.headers.location, docUrl, event, trace + 1);
         return;
      }
      logger.debug(sys.inspect(srcRes.headers));
      dst.headers['content-type'] = srcRes.headers['content-type'];
      dst.headers['content-length'] = srcRes.headers['content-length'];
      var dstReq = dst.client.request('PUT', dst.path, dst.headers);
      dstReq.on('response', function(dstRes){
         logger.debug('CouchDB repsonse: ' + dstRes.statusCode);
         var buff = '';
         dstRes.on('data', function(chunk){
            buff += chunk;
         });
         dstRes.on('end', function(){
            logger.info('ends with ' + buff);
            var obj;
            try{
               obj = JSON.parse(buff);
            }catch(e){
               logger.error('CouchDB returns invalid JSON: ' + buff);
            }
            event.emit('end', obj);
         });
      });

      var buff = '';
      var progress = 0;
      var size = 0;
      var totalSize = srcRes.headers['content-length'];
      srcRes.on('data', function(chunk){
         if(srcRes.statusCode == 200 ){
            dstReq.write(chunk);
            size = size + chunk.length;
            event.emit('progress', size, totalSize);
         }else{
            buff += chunk;
         }
      });
      srcRes.on('end', function(){
         dstReq.end();
         if(srcRes.statusCode != 200 ){
            logger.error('postAttachmentFailed with {status} ({url})'.format({status: srcRes.statusCode, url: fileUrl}));
            logger.error("{data} ({url})".format({url:fileUrl, data:buff}));
         }
      });
   });
   srcReq.end();
   return event;
}